<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="jquery-3.7.1.min.js"></script>
</head>
<body>
    <input type="text" id="username">

    <script>
        //键盘事件
        $("#username").keydown(function(e){
            console.log(e.keyCode);
            
        })



        $("#username").keyup(function(e){
            console.log(e.keyCode);
            
        })

        $(".username").keypress(function(){
      console.log("键盘");
     })
    </script>
</body>
</html>